I love my foldable and am kinda excited at the idea of graphene OS!

I do worry about the cost, of repair or replacement.

I'm fortunate I can do my own repairs, but still the parts are pricey as you say.

For me the utility of the big screen is worth it!

Depending on how you use your phone this concern may not be as big as you think, flip phones spend the vast majority of time with the screen closed and protected. My partner got a 2024 Razr and has been using it daily for 1.5yr without any scratches or other screen related issues (there's some expected slowness from the clunky MTK processor of course). I was skeptical of the durability at the time but for $450 with an 18mo warranty including accidental damage figured it was worth the risk. The technology is much more mature than I realized.

I have and still enjoy my fold, but I took into account the cost of insurance when I got it because I knew the inner screen was susceptible to damage. Had it for two years and just having some minor issues at the edge where it folds now, probably going to about land close to evenly on the cost to insure over the 2 years vs out of pocket repair. They are getting better with the tech tho, and with wider adoption I expect repair costs to decrease in the future. Triple folds are now going to be the area where you're asking for trouble.